SC, Thanks for the info. With these vintage tubes, I wonder if I should have them tested on a tube tester, or could doing that risk damaging the tube? Thanks.
People collect some unusual things, and it's amazing they even have counterfeit tubes out there. Growing up my dad built some large flying model airplanes powered by gas engines, and apparently some of the engines are highly collectible. People will collect just about anything.
I have some hand made fishing lures used by my great grandfather for ice fishing on the Mississippi River. I thought these were really unusual, but alas, Ebay has whole section on hand made lures.
In addition to more 'normal' items, like coins, records, concert posters, artwork, gems/minerals, etc, I have a some vintage slide rules from my dad's engineering days. Up until the 1970s, the world's airplanes, spacecraft, and satellites were designed by engineers using slide rule accuracy, since there were no pocket calculators or CAD/CAM yet. He has numerous space related items, test materials from satellite heat shields (thermo-protection), an award/medal from the CIA for the early spy satellite program, a piece of the first US satellite recovered from orbit, etc. Might be interesting for an episode of Pawn Stars or the Antiques Roadshow :o)